BTS short story collection

I found an article I wanted to see

I miss my senior from the swimming club, Seokjin Kim...
With the slightly tall female protagonist and Seokjin...

The female lead seems to be playing table tennis or archery, and the senior Kim Seok-jin or the younger Kim Seok-jin is good at swimming... They don't seem to be the same age, but it's already delicious. Yum yum.

Would you call me Yeojuya or Sunbae? ㅠ

Anyway, that's what I heard...